Drill bit stabilizer device

ABSTRACT

A stabilizing sleeve device for an impact drill bit used in underground drilling operations. The cylindrical tubular device has arcuate keys on a bottom edge for interlocking with keyways in the shoulder of a hammer drill bit and a locking key groove in its top edge.

CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional PatentApplication Serial No. 60/190,931, filed Mar. 21, 2000.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] The present invention relates generally to drill bits. Moresspecifically, the invention is a stabilizing sleeve for an impact drillbit used in underground drilling operations.

[0004] 2. Description of Related Art

[0005] The related art of interest describes various drill bit sleeves,but none discloses the present invention. There is a need for astabilizing sleeve for prolonging the life of the impact drill bit whenbeing used underground. The related art of interest will be discussed inthe order of perceived relevance to the present invention.

[0006] U.S. Pat. No. 5,065,827 issued on Nov. 19, 1991, to John A.Meyers, et al. describes a hammer bit retention tool for ahammer-percussion bit assembly comprising a retaining member or sleevedesigned to fit around a modified driver sub and drill bit head. Theretainer has an internal distal shoulder adapted to extend around thehead section of the bit and functions to grab the severed bit headsection upon lifting of the drill string while not interfering with thenormal operation of the assembly. An optional pin can be inserted in theretaining member above the internal distal shoulder as an additionalsecurement. The hammer bit retention tool is distinguishable for itsmodified retaining member with an internal distal shoulder and optionalpin structure.

[0007] U.S. Pat. No. 5,803,192 issued on Sep. 8, 1998, to Ardis L. Holtedescribes a drill bit retainer for a down hole hammer assembly. Thetwo-part segmented retainer sleeve comprises an upper ring portion tolimit bit travel and an extended lower skirt portion for confinementwithin a component of the hammer assembly to prevent loss of theretainer sleeve and drill bit in the event of barrel separation. Whenthe chuck unscrews from the barrel, the retainer sleeve will remain inplace due to the extended skirt still being radially confined. If thepartial separation between the chuck and the barrel, clockwise rotationof the barrel on the chuck will cure the separation. The drill bitretainer is distinguishable for its required halved configuration andthe ring and skirt portions.

[0008] U.S. Pat. No. 5,647,447 issued on Jul. 15, 1997, and U.S. Pat.No. 5,699,867 issued on Dec. 23, 1997, to William L. Jones describe abit retention device for a bit and chuck assembly of a down-the-holepercussive drill for retaining the head section of the bit should thehead section separate from the shank portion during drilling operations.A wear collar is positioned at the end of the drill string casing andholds the chuck by a peripheral shoulder and an optional pin. The wearcollar has a distal inward facing flange which retains a flexible ring.The bit has a retaining shoulder which secures the broken bit fromescaping from the wear collar. The wear collar can be rotatable withrespect to the chuck. If the wear collar is non-rotatable, the chuck andthe wear collar can be a single piece or locked by a pin. The wearcollar is distinguishable for its requirement for an inner shoulder, anoptional pin, and a flexible retaining ring for the inward facing distalflange. The drill bit must also have a cooperating peripheral retainingshoulder.

[0009] U.S. Pat. No. 5,390,749 issued on Feb. 21, 1995, to Leland H.Lyon describes an apparatus for positioning a split retaining ring in adown-hole percussive drill. The positioning * apparatus isdistinguishable because no protective sheath is provided.

[0010] U.S. Pat. No. 4,961,469 issued on Oct. 9, 1990, to Kenneth L.Larsson et al. describes a drill string element for use in top hammerpercussive drilling. comprising tubes connected by alternating conicalthreads and cylindrical threads. The drill bit is prevented from fallingout of the drill string by a stop ring. The drill string element isdistinguishable for lacking a sleeve.

[0011] U.S. Pat. No. 4,727,944 issued on Mar. 1, 1988, to-Clifford: C.Bottoms describes a percussion drill string assembly including a cagethreaded to the outer barrel and containing lubricant and steel ballbearings which contact the inner barrel connected to the chuck and drillbit. The cage portion is distinguishable as there is no provision forpreventing the loss of a broken drill bit.

[0012] U.S. Pat. No. 4,474,488 issued on Oct. 2, 1984, to Cletis P.Pinkerton et al. describes a retainer system for a roof-mine tool bitwhich is provided with keyway recess portions adapted to telescopinglyand/or rotatably receive an interlocking relationship thereincorrespondingly shaped keyway members carried by the drill steel member.The retainer system is distinguishable for lacking a sheath member.

[0013] U.S. Pat. No. 3,322,216 issued on May 30, 1967, to Ewald H. Kurtdescribes an anvil for a percussive drill having longitudinal notchesfor interlocking with the chuck grooves or flutes. The anvil element hasan outer wear sleeve which is distinguishable for lacking a protectivemeans for preventing loss of a broken drill bit.

[0014] None of the above inventions and patents, taken either singly orin combination, is seen to describe the instant invention as claimed.

SUMMARY OF THE INVENTION

[0015] The invention is a stabilizing sleeve device for an impact drillbit used in underground drilling operations. It is in the configurationof a cylindrical tubular device with a bottom edge having keystherearound. These keys interlock with keyways in the shoulder of ahammer drill bit. The cylindrical tubular device has a locking keygroove in its top edge.

[0016] Accordingly, it is a principal object of the invention to providea stabilizing sleeve device for a drill bit.

[0017] It is another object of the invention to provide a stabilizingsleeve device for a drill bit used in underground drilling.

[0018] It is a further object of the invention to provide at cylindricalstabilizing sleeve device having keys on one edge for interlocking withslots on the drill bit.

[0019] Still another object of the invention is to provide a cylindricalstabilizing sleeve device having a locking key groove on an oppositeedge for fitting the locking key portion of the chuck.

[0020] It is an object of the invention to provide improved elements andarrangements thereof in an apparatus for the purposes described which isinexpensive, dependable and fully effective in accomplishing itsintended purposes.

[0021] These and other objects of the present invention will becomereadily apparent upon further review of the following specification anddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022]FIG. 1 is a side elevational view of a conventional drill bit witha stabilizer shown in ghost lines, according to the present invention.

[0023]FIG. 2 is a perspective view of the inventive bit stabilizerdevice.

[0024]FIG. 3 is a perspective view of a conventional chuck.

[0025] Similar reference characters denote corresponding featuresconsistently throughout the attached drawings.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0026] The present invention is directed to an impact drill bitstabilizer sleeve device 10 shown in FIG. 2 as comprising a cylindricalmetal tube 12 having a top edge and a bottom edge 16. A locking keygroove or notch 18 is located on the inside of the top edge forpermitting the use of a locking key 20 located in the chuck 22 proximateto the bottom 24 thereof shown in FIG. 3.

[0027] The bottom edge 16 of the cylindrical device 10 has three innerindented arcuate keys 26 (FIG. 2) formed for interlocking with the threeexternal arcuate slots or keyways 28 in the shoulder 30 of anunderground drill bit head 32 of a hammer bit 34 illustrated in FIG. 1.

[0028] After the hammer bit 34 is inserted in the chuck 22, thestabilizer sleeve device 10 is slipped over the chuck and hammer bit toengage the bit's keyways 28 with its keys 26. The stabilizer sleevedevice 10 is rotated one-half turn to align the locking key 20 in thechuck 22 with the locking key groove 18 to permit access to the lockingkey of the chuck. With the chuck 22 threaded into the hammer, the keys26 of the stabilizer sleeve device 10, interlocked with the keyways 28of the shoulder 30 of the hammer drill bit 32, stabilize the bottom halfof the hammer bit 34 to increase its life and lessen the loss of abroken hammer bit within the downhole.

[0029] It is to be understood that the present invention is not limitedto the sole embodiment described above, but encompasses any and allembodiments within the scope of the following claims.

I claim:
 1. A drill bit stabilizer device system comprising: acylindrical metal tube having a top edge and a bottom edge; said topedge having a locking key groove in an inner surface; said bottom edgehaving a plurality of substantially equidistantly spaced arcuate keys inan inner surface; and a shoulder of an underground hammer drill bit headhaving a plurality of substantially equidistantly spaced arcuate keywaysfor interfitting the keys in the cylindrical metal tube, for stabilizinga hammer drill bit during a downhole drilling process.
 2. The drill bitstabilizer device according-to claim 1, including a locking key grooveon an inner surface of a top edge of the cylindrical metal tube adaptedfor access to the locking and unlocking of the hammer drill bit in thechuck.
 3. The drill bit stabilizer device according to claim 1, whereinthe number of keyways and keys is three.